Insider Threats: Protecting Ourselves From Ourselves

As we defend our networks from sophisticated external threats, we sometimes overlook perhaps a greater threat lurking within. This threat has a badge into the building and a password onto the network. It works amongst us, setting up servers, configuring software, and sometimes even deciding upon policies to protect us. In my opinion, insider threat is under-scrutinized by the security community, leaving networks vulnerable to compromise by their own employees, especially those with privileged access.

Identify: The Many Faces of Insider Threat

Insider threat is not a new problem. Some of the most complex cyber security breaches we see start with an insider gone rogue. Yet very little is being done to combat the problem. In fact, it seems to be an afterthought with most teams I work with. Is this because insider threat is notoriously difficult to detect? Or are we simply too busy working on those pesky external threats?

Insider threat has many faces. The classic disgruntled employee, blackmail victim, and careless user are all easily recognizable. But there is a small group of users that perhaps pose an even greater threat to our corporations, while typically getting the least amount of scrutiny. I am talking about the privileged access users, who benefit from unencumbered access to the most sensitive data and systems on networks. Yet system administrators, network engineers, and even CISOs can pose the greatest threat to our organizations. Are we watching them? How do we protect ourselves from ourselves?

This type of threat can sometimes be the hardest to detect as privileged users operate under a cloak of legitimacy. They typically have the knowledge and ability to evade detection and are often presumed innocent until proven guilty. It might come as a surprise, then, that we discover incidents involving privileged access users almost every week.

Take, for instance, the systems administrator who decides to send log files to his or her home machine to work after hours, or over the weekend. Or the data center administrator who makes a configuration change to numerous servers to mine cryptocurrency. And my favorite will always be the CISO using a commercial VPN -against corporate policy - to view inappropriate online content. The majority of the incidents we see are classic examples of non-malicious insider threat; users creating shortcuts to make their jobs easier, but ultimately opening their companies up to vulnerability.

Detect: Where’s Waldo…

Regardless of motivation, all insider threats share one very common trait: the user’s device starts to exhibit patterns of anomalous behavior, which AI technology can instantly recognize as threatening. Sometimes these deviations from the device’s normal ‘pattern of life’ will be very notable. Yet other times these indicators of a compromise are so imperceptible as to go undetected by traditional tools, rigidly programmed to only catch known threats. However, regardless of just how subtle the indicators may be, there will always be tangible differences between the behavior of these and other similar devices on the network.

In this data-driven world we live in, finding the evasive needle in an ever-growing haystack can seem nearly impossible. Our networks are getting more complex and organic by the day. With a massive cyber security and IT skills shortage, employing new and more efficient ways to combat old problems is the only answer. This is where machine learning and AI excel, when used properly.

Tools that employ genuine machine learning that learns from live data can drastically augment and improve current log analysis platforms. As many of us in the industry are aware, a good attacker will know how to avoid leaving incriminating breadcrumbs behind, often times modifying logs to hide their whereabouts. Log analytics is a powerful tool, but only as powerful and accurate as the data fed to it. A tool at the network level can ensure the accuracy of log analytics, quickly detecting any discrepancies between log analytics and network activity in real time. Network traffic does not lie.

React: Practice What You Preach

It does not matter how fast or efficiently we detect these incidents and problems if we don’t properly enforce our own policies. Privileged users need to be held to a higher standard, as they can cause the most damage to a company. Failure to do so substantially increases the risks of a serious insider incident. Practice what you preach and if you preach poor security, expect breaches and attacks to follow.

But even if we have the most advanced security policies and enforcement mechanisms in place, human error is a fact of life and insider threat – be it malicious or accidental – can never be fully eradicated. AI cyber defense technology offers the best chance to catch even the most subtle changes in behavior and to stop in-progress attacks before they have wreaked havoc.

Justin Fier is the Director for Cyber Intelligence & Analytics at Darktrace, based in Washington D.C. With over 10 years of experience in cyber defense, Fier has supported various elements in the US intelligence community, holding mission-critical security roles with Lockheed Martin, Northrop Grumman Mission Systems and Abraxas. Fier is a highly-skilled technical officer, and a specialist in cyber operations across both offensive and defensive arenas.